This invention relates generally to artificial hearts, and more particularly to methods of control therefor.
Heart transplant is a course of action for patients with end stage heart failure, a leading cause of premature death. Because of the unavailability of donor hearts, electromechanical blood pumping systems are being developed and are increasingly coming into use. These devices can provide a bridge to transplant, bridge to recovery, or as a permanent treatment for patients who may not receive a donor heart. Most such patients will be treated with a ventricular assist device (“VAD”), which draws blood from the left or right ventricle, and discharges to the aorta or pulmonary artery, respectively. Some patents require a total artificial heart (TAH) as either a bridge to transplant, or as a permanent therapy.
One known type of TAH is a continuous flow total artificial heart (CFTAH) which includes two centrifugal pumps on one rotor supported on a hydrodynamic bearing and driven by a single motor. The CFTAH replaces the ventricles of the heart, and delivers blood flow to both the systemic (left) and pulmonary (right) circulation of the patient. An example of such a CFTAH is described in U.S. Patent Application Publication 2007/0253842.
While this type of CFTAH can be operated under external control, there is a need for physiologic control therefor, preferably using the least number of sensors.